Characterization and function analysis of a cold-induced AmCIP gene encoding a dehydrin-like protein in Ammopiptanthus mongolicus.

A cDNA clone was isolated after difference screening from cotyledons of two-week cold-treated Ammopiptanthus mongolicus. The full-length cDNA sequence [designated as AmCIP (A. mongolicus cold-induced protein) gene] was 806 bp long and contained a 465 bp open reading frame (ORF) encoding a 16.6 kD protein of 154 amino acids. Bioinformatic analyses indicated that CIP belongs to dehydrin family with the features of high hydrophilicity, a helix K-segment, a long Gly-rich region and a phosphorylatable tract of Ser as well as deficiency in Cys and Trp. The expression of CIP gene increased after two weeks of cold treatment and more expression was detected in radicle than in cotyledon. And PCR amplification of the AmCIP gene from genome of A. mongolicus revealed this gene has no intron. Function prediction suggested this protein seems to protect the stabilization of membrane structure and prevent macromolecular coagulation or sequestrate calcium ions by association or disassociation with membrane under low temperature conditions.     

鸡减蛋综合征病毒（EDSV—76）末端前体蛋白的基因结构分析

从中国发病鸡群中分离的鸡减蛋综合征病毒弱毒株ＡＡ－２,经常规方法提取其病毒核酸后,组建了完整的限制性内切酶ＰｓｔＩ及ＨｉｎｇⅢ水解片段的基因文库,并对其中ＨｉｎｄⅢ,－ＳａｃⅠ进行了序列测定。同源比较分析证明：其Ｌ链含编码病毒末端前体蛋白,容量为５８０个氨基酸残基的开放读码框架。     

小RNA病毒和小DNA病毒的三维结构模型

本文综述了小RNA病毒和小DNA病毒的主要结构特征,绘制出了它们的三维结构模型,从中找出了两者间的共同点和差异,为进一步研究两种病毒提供了依据。     

外源基因表达造成的群体感应细菌生存压力的建模分析

外源基因的表达及其对细菌种群的影响对于群体感应系统和合成生物学产业的研究具有重要意义。然而,人们对于表达外源蛋白的细菌本身的行为模式仍然知之甚少。为了研究菌落生长和外源基因表达的过程究竟受到哪些因素的影响,文中测量了受Lux类受体调控的外源基因在N-酰基高丝氨酸内酯 (N-acyl homoserine lactone,N-AHL) 信号分子诱导下的表达,并模拟了其对细菌种群动态的影响。文中建立了一个假设性的数学模型,对信号分子诱导表达下细菌种群生长受影响的现象进行了分析。先前的研究通常将细菌种群生长受群体感应系统影响的现象归咎于合成群体感应信号分子的消耗与N-AHL信号分子的毒性,文中提供了对于这种生存压力的另一种可能的解释。     

Regulatory perspective of antibiotic biosynthesis in Streptomyces

<正>Streptomycetes are Gram-positive bacteria with high GC DNA content. They produce the most abundant secondary metabolites including over two-thirds of the clinically used antibiotics of natural origin (Barka et al., 2016), for example,the important broad-spectrum antimicrobials oxytetracycline(OTC) and chlortetracycline, which are the tetracycline antibiotics, produced by Streptomyces rimosus and Strepto-     

CTSB promotes porcine preadipocytes differentiation by degrading fibronectin and attenuating the Wnt/β-catenin signaling pathway

The process of preadipocytes differentiation plays a vital role in adipose tissue expansion and many factors are involved in this event. Cathepsin B (CTSB), secreted from lysosome, has been reported in regulating a variety of physiological processes. In this study, we demonstrated CTSB promotes lipid accumulation and adipogenic genes expression in porcine primary preadipocytes by degrading fibronectin (Fn), a key component of extracellular matrix. Lithium chloride (LiCl) is an activator of Wnt/β-catenin signaling through stabilizing β-catenin. We found that CTSB can relieve the anti-adipogenic effects of LiCl, indicating that CTSB could impact Wnt/β-catenin signaling pathway. Interestingly, Fn is an important target gene of Wnt/β-catenin. So we considered that CTSB promote preadipocytes differentiation by suppressing these two pathways.     

Systematic profiling of staralog response to acquired drug resistant kinase gatekeeper mutations in targeted cancer therapy

Amino Acids - Kinase-targeted therapy has been widely used as a lifesaving strategy for cancer patients. However, many patients treated with targeted cancer drugs are clinically observed to rapidly...     

MAPK signaling regulates c‐MYC for melanoma cell adaptation to asparagine restriction

Amino acid restriction is among promising potential cancer treatment strategies. However, cancer cells employ a multitude of mechanisms to mount resistance to amino acid restriction, which impede the latter’s clinical development. Here we show that MAPK signaling activation in asparagine‐restricted melanoma cells impairs GSK3‐β‐mediated c‐MYC degradation. In turn, elevated c‐MYC supports ATF4 translational induction by enhancing the expression of the amino acid transporter SLC7A5, increasing the uptake of essential amino acids, and the subsequent maintenance of mTORC1 activity in asparagine‐restricted melanoma cells. Blocking the MAPK‐c‐MYC‐SLC7A5 signaling axis cooperates with asparagine restriction to effectively suppress melanoma cell proliferation. This work reveals a previously unknown axis of cancer cell adaptation to asparagine restriction and informs mechanisms that may be targeted for enhanced therapeutic efficacy of asparagine limiting strategies.